Support and grounding structure

ABSTRACT

There is provided a heatsink assembly. The heatsink assembly comprises: a processor mounted onto a circuit board; a heatsink located in thermal contact with the processor at the side of the processor opposite circuit board; and an electromagnetic shielding member located between the circuit board and the heatsink. The electromagnetic shielding member is releasably attached to the circuit board. Additionally, or in the alternative, the heatsink is biased toward the processor by a load spring and the electromagnetic shielding member is configured to provide a spring force between the circuit board and the heatsink, counter directional to the bias from the load spring.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to support and grounding structuresand in particular, but not exclusively to central processing unit coolersupport and grounding structures within a computer system.

[0002] One application for the present invention relates to computersystems where physical robustness is required. Examples of such systemsinclude portable computing (so-called “laptop” and “notebook” computers)and in multiple processing engine server systems having replaceableprocessing engine cartridges or “blades”. Blade based computer systemsare typically high density computer systems, which systems are typicallyrack mountable, with one or more processor systems occupying a shelf inthe rack. In blade computer systems physically robust blades may bereplaceable by unskilled workers and may be expected to be subjected tovigorous or rough handling by those workers. The trend in recent timesis to make the computers with smaller form factors. This means that morecomputers can be located in a rack. This has the advantage of increasingthe processing density within the racks, and also the advantage ofreducing the distance between the computer systems.

[0003] The present invention relates to providing robust and effectivecooling and grounding for a central processor unit within a computersystem

SUMMARY OF THE INVENTION

[0004] Viewed from a first aspect, the present invention provides aheatsink assembly. The heatsink assembly comprises: a processor mountedonto a circuit board; a heatsink located in thermal contact with theprocessor at the side of the processor opposite circuit board; and anelectromagnetic shielding member located between the circuit board andthe heatsink. The electromagnetic shielding member is releasablyattached to the circuit board. This arrangement provides for asimplified procedure for assembling the assembly in that the shieldingmember is held in place in its own right, such that it is held in placeduring later addition of the heatsink.

[0005] In one embodiment, the shielding member is held in place by catchmembers which are operable to be passed through apertures in the circuitboard to grip against the reverse side of the circuit board. Thisembodiment provides further simplification to a procedure for assemblingthe assembly in that no separate, small, difficult to handleinterlocking parts such as nuts and bolts are required for the fixing ofthe shielding member.

[0006] In another embodiment, the apertures through the circuit boardare slots having a long dimension and a short dimension wherein theslots are formed through the motherboard having an orientation accordingto which the long dimension is arranged to be substantiallyperpendicular to a nearest edge of the processor. This embodimentprovides that the apertures present a low obstruction to the forming ofpaths or tracks within or on the circuit board radiating away from theprocessor.

[0007] Viewed from a second aspect, the present invention provides aheatsink assembly. The heatsink assembly comprises: a processor mountedonto a circuit board; an electromagnetic shielding member locatedadjacent the side of the circuit board having the processor mountedthereto; and a heatsink in thermal contact with the processor at theside of the processor opposite the circuit board. The heatsink is biasedtoward the processor by a load spring and the electromagnetic shieldingmember is configured to provide a spring force between the circuit boardand the heatsink, counter directional to the bias from the load spring.This arrangement provides for stability of the heatsink when thearrangement is fully assembled. The force from the load spring keeps theheatsink in place on top of the processor and the force from theshielding member acts against any tilting of the heatsink relative tothe processor to maintain good thermal contact between the heatsink andthe processor. This arrangement also helps avoid damage to the processorcause by non-orthogonal loading thereof.

[0008] In one embodiment, comprising an attachment member having aloading portion configured to support the load spring and an attachmentportion configured to secure the attachment member to the circuit board.This arrangement provides for the load spring to act in relation to thecircuit board, thereby creating a self-contained structure.

[0009] In another embodiment, a stiffening member is provided forreinforcing the circuit board against the force applied by the loadspring. This arrangement provides for the circuit board to be protectedfrom flexing and fracture under the load of the load spring.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Embodiments of the present invention will be describedhereinafter, by way of example only, with reference to the accompanyingdrawings in which like reference signs relate to like elements and inwhich:

[0011]FIG. 1 is a schematic cross section view of a cooling andgrounding structure according to a first example;

[0012]FIG. 2 is an exploded schematic perspective view of the coolingand grounding structure of FIG. 1;

[0013]FIG. 3 is a schematic perspective view of part of the cooling andgrounding structure of FIG. 1;

[0014]FIGS. 4a, 4 b and 4 c are views of part of the cooling andgrounding structure of FIG. 1;

[0015]FIG. 5 is a schematic cross section view of a cooling andgrounding structure according to a second example; and

[0016]FIG. 6 is a schematic perspective view of part of the cooling andgrounding structure of FIG. 4.

[0017] While the invention is susceptible to various modifications andalternative forms, specific embodiments are shown by way of example inthe drawings and are herein described in detail. It should beunderstood, however, that drawings and detailed description thereto arenot intended to limit the invention to the particular form disclosed,but on the contrary, the invention is to cover all modifications,equivalents and alternatives falling within the spirit and scope of thepresent invention as defined by the appended claims.

DESCRIPTION OF PARTICULAR EMBODIMENTS

[0018] Embodiments and examples are described hereafter by way ofexample only in the following with reference to the accompanyingdrawings.

[0019] Shown in FIG. 1 is a schematic cross section view of a supportand grounding structure 1 according to a first example. FIG. 2 shows thesupport and grounding structure of FIG. 1 from an exploded perspectiveviewpoint. FIG. 3 shows part of the support and grounding structure ofFIG. 1 from an assembled perspective viewpoint. FIG. 4a shows a planview of a shielding member of the support and grounding structure ofFIG. 1 and FIGS. 4b and 4 c show sections through the shielding memberof FIG. 4a take through lines I-I and 11-11 respectively.

[0020] The grounding and support structure 1 is provided for a processor3. The processor 3 of the present example has an exposed processor die 5mounted onto a substrate 7.

[0021] Examples of processors having this type of design include Celeronseries processors manufactured by Intel Corporation and Athlon™ andDuron™ series processor manufactured by Advanced Micro DevicesCorporation (AMD). The processor 3 of the present example is retained ina processor socket 9. The socket 9 is attached to a circuit board 11,typically a printed circuit board (PCB). Such an arrangement of aprocessor in a socket on a circuit board is well known to the skilledaddressee and therefore no further description of such arrangements willbe presented here. The socket of the present example is a socket of thewell-known Zero-Insertion-Force (ZIF) type, although any other IC sockettype may be used—as appropriate to the processor used.

[0022] The circuit board 11 has formed therethrough at positions locatedabout the socket 9, a plurality of holes 13 and slots 15. These holesand slots provide attachment locations for further components of thegrounding and support structure of the present example.

[0023] ElectroMagnetic interference (EMI) can cause many problems withincomputer systems. In particular, a central processor unit of a computersystem is a major source of electromagnetic interference. This is atleast in part due to the high clock frequencies used in currentmicroprocessors. For example, many microprocessors run at a core clockfrequency of 2 GHz or greater. This is compared to a clock frequency ofapproximately 200-400 MHz for many other components of a computersystem. Therefore, in the present example, an EMI shielding “ring” isprovided around all sides of the processor to limit EMI to othercomponents of the computer system. Ground planes within the circuitboard provide such shielding below the processor, and a heatsink(described below) may be grounded to provide such shielding above theprocessor. To provide EMI shielding around the sides of the processor, aso-called EMI shielding gasket may be provided.

[0024] In the present example, a shielding gasket is provided in theform of EMI shielding member 17. The shielding member 17 comprises aring of conductive material configured to surround the processor 3. Theshielding member 17 is grounded to provide EMI shielding. Shieldingmember 17 is, in the present example, secured to the circuit board 11 byresilient catch members 19. The catch members 19 extend through theslots 15 in the circuit board and, in the present example, through slots21 through a bolster plate 23 provided behind the circuit board 11 toprovide structural support to the area of the circuit board 11 havingthe processor socket 9 mounted thereto. The catch members 19 areresiliently biased toward the position shown in FIG. 1, but may beforced inward (toward the processor socket position) to allow passagethrough the slots 15 and 21 to reach the retaining position shown inFIG. 1. The provision of the catch members allows for a quick and simpleassembly procedure for the EMI shielding member 17 and the bolster plate23 to the circuit board 11. Both the EMI shielding member 17 and thebolster plate 23 are held in position relative the circuit board 11 andprocessor 3 to simplify a procedure for fitting of a heatsink (describedbelow). Additional benefit is provided in that the EMI shielding member17 and bolster plate 23 are retained in position about the circuit board11 without recourse to additional securing parts, thereby obviating anyrequirement for screws, bolts, nuts or other separate securing means.

[0025] Thus use of slots and catch members to retain the EMI shieldingmember in position provides a benefit that the slots may be much smallerin a width dimension than a hole for receiving a retaining screw, forexample. By arranging these slots such that the width dimension of theslot is substantially parallel to the nearest edge of the processorsocket, a minimum of obstruction is provided within the circuit board totracks or lines of the circuit board radiating out from the socket.

[0026] Use of slots and catch members to retain the EMI shielding memberin position also simplifies an assembly procedure for the support andgrounding structure. The use of a retaining member provides a situationwhere the shielding member (and possibly also the bolster plate) is heldin position in its own right, thereby simplifying subsequent attachmentof a heatsink. Also the slot and catch member configuration provides fora push-fit type assembly procedure to be used to secure the partstogether, thereby avoiding a requirement for small separate parts suchas nuts and bolts to be used.

[0027] The EMI shielding member 17 is (as is clearly shown in FIGS. 2, 3and 4) a three-dimensional structure configured to have physical contactwith the circuit board 11 and a heatsink above (described below).

[0028] Located on top of the processor 3 is a heatsink 25. The heatsink25 of the present example comprises a heatsink base 27 and heat transferfins 29. In order that the heatsink provide efficient cooling for theprocessor die 5, the heatsink is placed in direct thermal contact withthe die. As the skilled addressee will appreciate such direct thermalcontact typically comprises mounting the heatsink directly onto theprocessor die and may comprise the use of a layer of thermallyconductive grease, state change thermal compound or other heat transferfacilitator between the die and the heatsink. The die of exposed dieprocessors is typically somewhat delicate in nature. In particular,whilst the die is capable of receiving a considerable force thereon tokeep a heatsink securely in place, such force should be appliedperpendicular to the plane of the die. Any substantial force acting in adirection other than perpendicular to the plane of the die and inparticular any force on the edges or corners of the die may causephysical distortion or damage to the die, thereby causing permanentprocessor failure. Thus the heatsink 25 is arranged to be mounted withthe plane of the heatsink base 27 substantially parallel to the plane ofthe die 5. Also, all attachment forces for holding the heatsink 25 inplace against the processor 27 are configured to sum to forces havingsubstantially no component acting parallel to the plane of the die 5.

[0029] In the present example, the heatsink 25 is held in place againstthe processor die 5 by a plurality of attachment bolts 33. Eachattachment bolt passes through a hole 31 through the heatsink base 27,through the holes 13 in the circuit board and through correspondingholes 49 through the bolster plate 23. The bolster plate 23 provides astrong member against which the attachment bolts 33 may be fastened,thus permitting secure attachment of the heatsink to the circuit board11 without causing undesirable flexing in the circuit board. Suchflexing may occur in a circuit board without a bolster plate if thestiffness of the circuit board is low compared to the force required tobe exerted to ensure good contact between the heatsink and theprocessor. In the event that the circuit board has sufficient inherentstiffness to prevent the board being damaged by bending caused byattachment of the heatsink, then the bolster plate may be omittedwithout compromising the functioning of the processor and a computersystem of which the processor is a part.

[0030] Each attachment bolt 33 comprises a head 35 which may be grippedto tighten or loosen the bolt relative its mountings, an unthreadedshaft portion 37 attached to the head 35, and a threaded shaft portion39 at the end of the unthreaded shaft portion distal the head 35. Ashoulder 41 is provided at the junction between the threaded andunthreaded shaft portions. Thus the attachment bolt 33 may be tightenedhard against a stop member (described below) to prevent over-tighteningof the bolt causing damage to the processor, circuit board or bolsterplate. Provision for overtightening protection is made as the mechanicaladvantage provided by a threaded bolt or screw can be considerablerelative to the resistance of a processor die to applied force. Eachattachment bolt of the present example is tightened into a collared nut47. The collar of the nut 47 extends through the holes 13 and 49 in thecircuit board and bolster plate (as shown in FIG. 3) and the top surfaceof the collar provides a surface for the shoulder 41 of the attachmentbolt 33 to be tightened against. The nut 47 has an internal thread forconventional thread interaction with the threaded portion 39 of the bolt33. The internal thread may extend along the whole length of the nut 47or may extend over only a part thereof. In the present example, the nut47 is a separate component to the bolster plate 23 and is arrangedcaptive thereto, although in alternative arrangements the nut may bearranged not captive to the bolster plate or may be formed as anintegral part of the bolster plate i.e. as a threaded hole.

[0031] To ensure that a substantially even force is applied to theheatsink 27 to maintain suitable contact pressure with the processor die5, a load spring 43 is provided on each attachment bolt 33. The loadspring 43 of the present example is a coil-type compression spring whichacts between the under surface of the head 35 of the bolt 33 and the topsurface of the heatsink base 27. Thus a constant predetermined load maybe applied to the top of the heatsink relative to the processor die toprovide a predetermined contact force between processor die andheatsink.

[0032] An additional feature of the EMI shielding member 17 notdescribed above is that of a balance spring. As noted above, the EMIshielding member of the present example is a three-dimensional structureconfigured to contact both the circuit board 11 and the heatsink 27 atdifferent points about the perimeter of the processor socket 9. Thisdual contact arrangement provides that the EMI shielding member 17 maybe configured to provide a resilient force between the circuit board 11and the heatsink 27, thereby acting counter to the force provided by theload springs 43. Balancing of the forces applied by the EMI shieldingmember 17 and the load springs 43 provides a stabilizing effect for theheatsink 27. As the skilled addressee will appreciate, this stabilizingeffect will be greatest in arrangements where the spacing of the contactpoints between EMI shielding member 17 and the heatsink 27 and thelocations of the attachment bolts 33 are all arranged substantiallyradially equally about the processor die 5 at substantially equal radialdistance from the processor die 5, although other arrangements will alsoprovide a satisfactory stabilizing effect.

[0033] In the arrangement of the present example, additional robustnessof the support and grounding structure is provided. As the skilledaddressee will appreciate, in the system as described above, theheatsink is supported from below on the top surface of the processor die5, and is held down from above by the attachment bolts and load springs.

[0034] In the present example, the balance between the “upforce”provided by the EMI shielding member 17 and the “downforce” provided bythe load springs 43 is set such that a net “downforce” is provided toensure good thermal contact between the heatsink 27 and the processordie 5. Substantially no “upforce” is provided at a time when theheatsink 27 and processor die 5 are substantially parallel, but the EMIshielding member 17 is preloaded at such time. Thus in the event ofexternal dynamic forces (for example caused by vigorous handling of thecomputer system comprising the heatsink arrangement) causing thatparallel relationship to be removed, the EMI shielding member 17provides an upforce to a part of the heatsink 27 which has become closerto the circuit board 11 that that would be when then heatsink 27 andprocessor die 5 are substantially parallel. Thus the balance springfunction of the EMI shielding member 17 provides a stabilizing effect tothe heatsink 27. Thus in the event of rough or vigorous handling of acomputer system comprising the heatsink support and grounding structure,the heatsink may be maintained in good thermal contact with theprocessor die and the application to the processor die of a load in adirection not substantially perpendicular to the plane of the processordie may be avoided.

[0035] As the skilled addressee will appreciate, other arrangements ofbalanced downforce and upforce on the heatsink than those describedabove may be provided. An example of an alternative arrangement toprovide a grounding and stabilizing structure will now be described withreference to FIGS. 5 and 6.

[0036] Shown in FIG. 5 is a schematic cross section view of a supportand grounding structure 1 according to a second example and FIG. 6 showspart of the support and grounding structure of FIG. 5 from an assembledperspective viewpoint. In this second example integers shown in thefigures in common with integers of the first example will be accordedthe same reference numerals.

[0037] In the second example of the support and grounding structure 101,a processor 3 is provided in a socket 9 mounted on a circuit board 11. Aheatsink 27 is held in position against the processor die 5 byattachment bolts 33 which attach to nuts 47, which also hold a bolsterplate against the circuit board.

[0038] The present example also provides EMI shielding member 117, whichdiffers from the shielding member 17 of the first example. The EMIshielding member 117 of the present example comprises four individualmembers 117. One member 117 being attached to the circuit board abouteach side of the processor socket 9.

[0039] Another difference from the first example, is that the shieldingmembers 117 of the present example are secured to the circuit board 11and the bolster plate 23 using retaining screws 119, which interfaceswith corresponding nuts 120. The retaining screws 119 pass through holes115 and 121 in the circuit board 11 and the bolster plate 23respectively.

[0040] Use of nuts and bolts to retain the EMI shielding member inposition simplifies an assembly procedure for the support and groundingstructure. The use of a retaining means provides a situation where theshielding member (and possibly also the bolster plate) is held inposition in its own right, thereby simplifying subsequent attachment ofa heatsink.

[0041] Thus there have now been described two examples of a support andgrounding structure. The skilled addressee will appreciate than manydeviations from those examples may be made whilst still falling withinthe scope of the invention. For example, many of the elements of theabove-described examples may be substituted for equivalents oralternatives thereto and many other modifications may be made. Examplesof possible alternatives, equivalents and modifications are set outhereafter.

[0042] Although it has been described above that the top of the collarednut provides a stop member for the shoulder of the attachment bolt to betightened to, such a stop member may be provided alternatively, forexample by a separate washer, by an upstand from the top of the circuitboard or by the circuit board itself. In some arrangements, the stopmember may be omitted altogether and balancing of the load springs maybe provided by other means.

[0043] Although it has been described above to provide a bolster plate,this is not essential to the operation of the invention. For example, acircuit board may have sufficient inherent stiffness to resist theforces applied by the attachment bolts unaided. Alternatively, it may bedecided that there is insufficient space for a bolster plate within aparticular arrangement, or a certain amount of flexing of the circuitboard may be determined to be acceptable.

[0044] Although it has been described above to use resilient catchmembers or nuts and bolts to secure the shielding member to the circuitboard, many other fixing means may be used. For example, a deformabletab could be provided such that following passing the tab through theholes through the circuit board (and bolster plate if appropriate) thetab could be deformed to provide for retention of the shielding member.Also, the skilled addressee will appreciate that in place of bolts,screws may be used and that the terms “screw” and “bolt” are commonlyused interchangeably for any threaded fastening means.

[0045] As an option to the above-described examples, further oralternative cooling means may be provided. For example, a cooling fanmay be attached to the processor in this way with a separate heatsink assuch being omitted. Also, a cooling fan may be provided in addition tothe heatsink.

What is claimed is:
 1. A heatsink assembly comprising: a processormounted onto a circuit board; a heatsink located in thermal contact withthe processor at the side of the processor opposite circuit board; andan electromagnetic shielding member located between the circuit boardand the heatsink; wherein the electromagnetic shielding member isreleasably attached to the circuit board.
 2. The heatsink assembly ofclaim 1, wherein the electromagnetic shielding member is locatedsubstantially perimetrically about the processor.
 3. The heatsinkassembly of claim 2, comprising a plurality of individualelectromagnetic shielding members located in a perimetric pattern aboutthe processor.
 4. The heatsink assembly of claim 2, comprising a unitaryelectromagnetic shielding member configured to surround the processor.5. The heatsink assembly of claim 1, wherein the electromagneticshielding member is releasably attached to the circuit board by athreaded member.
 6. The heatsink assembly of claim 1, wherein theelectromagnetic shielding member is releasably attached to the circuitboard by a sprung catch.
 7. The heatsink assembly of claim 6, whereinthe circuit board comprises a slot configured to receive the sprungcatch, the slot being longitudinally arranged toward the nearest side ofthe processor, substantially orthogonal thereto.
 8. The heatsinkassembly of claim 1, wherein the processor is located in a socketattached to the circuit board.
 9. The heatsink assembly of claim 1,wherein the electromagnetic shielding member is electrically connectedto a ground connection of the circuit board.
 10. The heatsink assemblyof claim 1, wherein the electromagnetic shielding member is electricallyconnected to the heatsink.
 11. The heatsink assembly of claim 1, whereinthe electromagnetic shielding member is configured to provide a springforce between the circuit board and the heatsink.
 12. The heatsinkassembly of claim 11, wherein a resilient force is provided to cause theheatsink to press on the processor by a load spring.
 13. The heatsinkassembly of claim 11, comprising an attachment bolt configuredreleasably to mount the heatsink to the circuit board.
 14. The heatsinkassembly of claim 12, wherein the load spring and the electromagneticshielding member provide oppositely directed forces on the heatsink. 15.The heatsink assembly of claim 1, further comprising a bolster platelocated adjacent the side of the circuit board opposite the side havingthe processor mounted thereto
 16. The heatsink assembly of claim 15,wherein the electromagnetic shielding member is releasably attached tothe bolster plate through the circuit board.
 17. The heatsink assemblyof claim 16, wherein a common retaining means attaches theelectromagnetic shielding member to the circuit board and to the bolsterplate.
 18. The heatsink assembly of claim 15, comprising an attachmentbolt configured releasably to mount the heatsink to the bolster platethrough the circuit board.
 19. The heatsink assembly of claim 1, whereina layer of heat transfer facilitating material is provided between theprocessor and the heatsink.
 20. A heatsink assembly comprising:processor means mounted onto a circuit board; heatsink means located inthermal contact with the processor means at the side of the processormeans opposite the circuit board; and electromagnetic shielding meanslocated between the circuit board and the heatsink means; wherein theelectromagnetic shielding means is releasably attached to the circuitboard.
 21. A heatsink assembly comprising: a processor mounted onto acircuit board; an electromagnetic shielding member located adjacent theside of the circuit board having the processor mounted thereto; and aheatsink in thermal contact with the processor at the side of theprocessor opposite circuit board, the heatsink biased toward theprocessor by a load spring; wherein the electromagnetic shielding memberis configured to provide a spring force between the circuit board andthe heatsink, counter directional to the bias from the load spring. 22.The heatsink assembly of claim 21, comprising an attachment memberconfigured to secure the heatsink to the circuit board.
 23. The heatsinkassembly of claim 22, wherein the attachment member comprises a supportsurface and wherein the load spring is configured to act between theheatsink and the support surface.
 24. The heatsink assembly of claim 23,further comprising a stiffening member located adjacent the side of thecircuit board opposite the side having the processor mounted thereto.25. The heatsink assembly of claim 24, wherein the attachment member isconfigured to secure the heatsink to stiffening member through thecircuit board.
 26. The heatsink assembly of claim 21, wherein theelectromagnetic shielding member is releasably attached to the circuitboard.
 27. The heatsink assembly of claim 26, wherein an electromagneticshielding member is located substantially perimetrically about theprocessor.
 28. The heatsink assembly of claim 27, comprising a pluralityof individual electromagnetic shielding members located in a perimetricpattern about the processor.
 29. The heatsink assembly of claim 27,comprising a unitary electromagnetic shielding member configured tosurround the processor.
 30. The heatsink assembly of claim 26, whereinthe electromagnetic shielding member is releasably attached to thecircuit board by a sprung catch.
 31. The heatsink assembly of claim 30,wherein the circuit board comprises a slot configured to receive thesprung catch, the slot being longitudinally arranged toward the nearestside of the processor, substantially orthogonal thereto.
 32. A heatsinkassembly comprising: processor means mounted onto a circuit board;electromagnetic shielding means located adjacent the side of the circuitboard having the processor means mounted thereto; and heatsink means inthermal contact with the processor means at the side of the processormeans opposite circuit board, the heatsink means biased toward theprocessor by load spring means; wherein the electromagnetic shieldingmeans is configured to provide a spring force between the circuit boardand the heatsink means, counter directional to the bias from the loadspring means.
 33. A method for attaching a heatsink to a processormounted to a circuit board, the method comprising: inserting a processorinto a processor receiving location of a circuit board; providing anelectromagnetic shielding member on the circuit board at a positionperimetrically about the processor receiving location; attaching aheatsink to the circuit board such that the heatsink is held in thermalcontact with the processor by a resilient force; wherein theelectromagnetic shielding member is configured to provide a force onsaid heatsink counter to the force provided by said resilient force. 34.The method of claim 33, further comprising locating a load spring inposition adjacent said heatsink to provide said resilient force.
 35. Amethod for attaching a heatsink to a processor mounted to a circuitboard, the method comprising: inserting a processor into a processorreceiving location of a circuit board; attaching an electromagneticshielding member to the circuit board at a position perimetrically aboutthe processor receiving location; attaching a heatsink to the circuitboard such that the heatsink is held in thermal contact with theprocessor by a resilient force.
 36. The method of claim 35, wherein thestep of attaching the electromagnetic shielding member comprises a stepof passing a catch member through an aperture through said circuitboard, the catch member being configured to act against a reverse sideof the circuit board to provide retention.
 37. A processor heatsinksupport and grounding structure comprising: a processor mounted onto acircuit board; a heatsink located in direct thermal communication withthe processor at the side of the processor opposite circuit board; aload spring configured to bias the heatsink toward the processor; and anelectromagnetic shielding member located between the circuit board andthe heatsink; wherein the electromagnetic shielding member is releasablyattached to the circuit board and is configured to provide a springforce between the circuit board and the heatsink, counter directional tothe bias from the load spring.
 38. A processor heatsink support andgrounding structure comprising: processor means mounted onto a circuitboard; heatsink means for providing transfer of heat from said processormeans, located in direct thermal communication with the processor meansat the side of the processor means opposite circuit board; load springmeans for biasing the heatsink means toward the processor means; andelectromagnetic shielding means for providing shielding around saidprocessor means, located between the circuit board and the heatsinkmeans; wherein the electromagnetic shielding means is releasablyattached to the circuit board and is for providing a spring forcebetween the circuit board and the heatsink means, counter directional tothe bias from the load spring.